23,000-Year-Old Footprints and Coprolites in New Mexico Keep the Fierce Debate on Human Arrival in the Americas Alive!

In a fresh wave of evidence published in Science Advances (March 2026), researchers have strengthened the case for humans in North America at least 23,000 years ago—thousands of years before the Clovis culture—using both ancient footprints and coprolites (fossilized feces) from White Sands National Park, New Mexico.

The trackways, first reported in 2021 and now dated with 60+ new radiocarbon ᴀssays on embedded Ruppia seeds, show adults, teenagers, and children walking along a Pleistocene lakeshore between 21,000 and 23,000 years ago. Multiple track horizons confirm repeated visits over centuries. Most dramatically, five coprolites recovered from the same stratigraphic layers contain human DNA and pollen consistent with a diet of local plants and small game—directly proving the track-makers were anatomically modern humans.

Critics had questioned the footprint dates, suggesting the seeds could be older than the tracks. The new coprolites, however, provide independent chronological and biological confirmation. Lead author Matthew Bennett (Bournemouth University) states: “Footprints alone could be debated; feces cannot. These are the oldest directly dated human biological remains in the Americas.”

The discovery intensifies the long-running “pre-Clovis” versus “Clovis-first” controversy. While the genetic and archaeological mainstream once favored a ~13,000-year arrival via an ice-free corridor, White Sands now joins sites like Monte Verde (Chile) and Paisley Caves (Oregon) in pushing human presence back into the Last Glacial Maximum.

As more White Sands layers are excavated, the evidence continues to rewrite the earliest chapters of the American story—suggesting that small groups of hunter-gatherers reached the continent far earlier, and via more routes, than textbooks once allowed. The debate is far from over, but the footprints and feces keep marching forward.